Evaluating Wellbore Telemetry Systems

ABSTRACT

Evaluating wellbore telemetry systems. Multiple evaluation signals are serially transmitted to multiple serially connected components of a wellbore telemetry system disposed in a wellbore. Each component is addressable by a respective one of the multiple evaluation signals. In response to serially transmitting the multiple evaluation signals, multiple communication links to the multiple components are evaluated based on a respective multiple responses to the multiple evaluation signals.

TECHNICAL FIELD

This disclosure relates to wellbore telemetry systems.

BACKGROUND

Wellbore telemetry systems are used to exchange, e.g., power, command, communication signals (or combinations of them), between a system (e.g., a computer system) at a surface of a wellbore and a downhole tool positioned at a remote location inside the wellbore. The signals are used to perform operations including, e.g., powering the operation of the downhole tool and communicating information, e.g., collected by the tool, between locations downhole and the surface. The wellbore telemetry systems can be implemented, e.g., as a wired drill pipe wellbore telemetry system, an electromagnetic wellbore telemetry system, an acoustic wellbore telemetry system, or a wellbore telemetry system that includes transceivers coupled to sensors to transmit the signals.

In wired drill pipe telemetry systems, drill pipes that form a drill string are provided with electronics capable of passing the signals between the computer system at the surface and the downhole tool. To do so, such systems can include wires that form a communication chain that extends through the drill string. Repeaters (or signal repeaters) can be disposed at selected positions along the length of the wires. Each repeater is adapted to receive and retransmit signals communicated in either direction along the drill string, e.g., to provide sufficient signal amplitude at the downhole tool. A quality of the wellbore telemetry system can be affected by a quality of the repeaters implemented in the system.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example wellbore telemetry system that includes addressable components.

FIG. 2 illustrates example communication signals exchanged by an evaluation computer system and the addressable components.

FIG. 3 is a flowchart of an example process for evaluating an addressable component.

FIG. 4 is a flowchart of an example process for evaluating an addressable component.

FIG. 5 illustrates another example communication exchange by an evaluation computer system and addressable components.

FIG. 6 illustrates another example communication exchange by an evaluation computer system and addressable components.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

This disclosure describes evaluating wellbore telemetry systems, e.g., telemetry systems that include addressable components. A wellbore telemetry system includes signal transmission components to transmit signals, e.g., electromagnetic, optical, acoustic, pressure signals. Using the signal transmission components, fluid flow modulation components, and other similar components, the wellbore telemetry system communicates between the terranean surface and downhole locations in the wellbore, for example, to communicate measurements made by well logging tools, e.g., Measurement While Drilling (MWD) tool, a Logging While Drilling (LWD) tool, or other suitable tool, to the surface.

Certain wellbore telemetry systems, e.g., wired drill pipe telemetry systems, can include multiple addressable components disposed in series in the wellbore. The addressable components can receive, retransmit, and respond to signals communicated in either direction, i.e., uphole or downhole, in the wellbore. Operation of the wellbore telemetry system can depend on the performance of each addressable component included in the system, and the system can fail to operate or operate impaired if one or more of the components in the system is impaired (e.g., is faulty or not operating as expected). Without information on which addressable component in the system is impaired all the addressable components may need to be removed from the wellbore to make a repair.

This disclosure describes techniques to evaluate each addressable component included in a wellbore telemetry system, while the telemetry system is in the wellbore, to identify an addressable component that is impaired. Early identification of an impaired addressable component or impaired connection between two addressable components before removing all the addressable components from the wellbore can save rig time. For example, upon identifying an impaired addressable component or connection, the string of addressable components need be removed from the wellbore only to the position of the impaired addressable component. Furthermore, the various implementations described below also allow optimizing the wellbore telemetry system by alleviating transmission bottlenecks at the addressable components. The operator may configure the addressable components at their optimal performance configuration according to at least one criterion, e.g. power consumption levels and/or data rates, maximize data throughput by replacing faulty components, spacing communicating components more appropriately for the well design, and/or minimize the overall power consumption. When utilizing batteries for power sources, the operator may want to configure/operate the various implementations as to reduce the battery consumption of the at least one of the components meanwhile maintaining a data throughput requirement. In other implementations, the operator may want to extend the reach in measured depth for a specified number of components while maintaining a minimum data throughput requirement. The various implementations allow operators to receive information describing the downhole location of the fault or limitation in real time. Thus, these implementations afford the operator the opportunity of correcting or adjusting the system early on when drilling or tripping into the well and thereby minimize non-productive time when in the wellbore. For identifying faulty addressable components, one may implement and/or utilize the various implementations described here in addition to or en lieu of Time Domain Reflectometry (TDR)

FIG. 1 illustrates an example wellbore telemetry system that includes multiple addressable components, e.g., repeaters. A wellbore environment 100 includes a wellbore 102 in which a string 106, e.g., a drill string, is suspended, e.g., by a drilling rig 103. The string 106 can include multiple lengths of pipe coupled end-to-end (e.g., using threads or otherwise). The string 106 can include a tool 104 attached to a lower end that is disposed within the wellbore 102. For example, the tool 104 can be a bottom hole assembly, e.g., including a drill bit and other components for drilling, attached to an end of a drill string. The string 106 can include a logging instrument 108 near the tool 104. For example, the logging instrument 108 is a MWD tool and/or a LWD tool that collects data (e.g., gamma, directional or azimuthal data, resistivity data, and other suitable data) while the drilling tool drills through subsurface formations to extend the wellbore 102. The data describes, e.g., a location of the wellbore 102 and a subsurface formation that is being drilled to extend the wellbore 102.

A wellbore telemetry system 112 which includes multiple addressable components, e.g., repeaters, connected in a series is disposed in the wellbore 102. The addressable components include, e.g., a first addressable component 110 a, a second addressable component 110 b, a third addressable component 110 c, and additional addressable components (not shown). The wellbore telemetry system 112 includes multiple communication links that connect the multiple addressable components. The wellbore telemetry system 112 can also include equipment mid-string, e.g., sensors or other equipment operated by the wellbore telemetry system 112. An addressable component receives data from a downhole addressable component in the series via a communication link and transmits the data to an uphole addressable component in the series via another communication link, and vice versa.

Each addressable component can comprise of a receiver and a transmitter to receive and retransmit commands and/or data through the communication links between neighboring addressable components. For receiving, some addressable component implementations can comprise of any subset or combination of the following: a sensor to receive modulated pressure within the drilling fluid (e.g. strain gauge, piezoelectric quartz), an acoustic sensor for receiving modulated acoustic communications (e.g. microphone), a photo-sensitive diode receiving light of at least one frequency, and/or a first electrical contact receiving a modulated voltage potential applied from a remote location (e.g. tubular housing & ceramic spacer). For transmitting, any of the implementations can further comprise of any subset or combination of the following: a valve in contact with the drilling fluid modulating pressure within said fluid (e.g. rotor & stator), an acoustic actuator for creating acoustic communications (e.g. piezoelectric ceramic), a Light Emitting Diode (LED) emitting light (e.g. laser in contact with a fiber optic strand), and/or a second electrical contact applying a modulated voltage potential in contact with a media conducive to current propagation within (e.g. copperwire, rock formation with water within its pore space with a non-zero salinity). Additional implementations can further comprise of at least one battery configured to power said receiver and/or transmitter.

In Measurement While Drilling (MWD), mud pulse, electromagnetic or acoustic applications (or combinations of two or more of them), multiple addressable components can mechanically fasten to multiple drill pipe sections. The mechanical fastening can comprise of a screw-type fastener on at least one end “female” threaded as to receive a “male” threaded counterpart of a first section of drill pipe. Additional implementations can further comprise of a “male” threaded counterpart as to insert into a “female” threaded counterpart of a second section of drill pipe. A preferred implementation can comprise of one “male” threaded end and one “female” threaded end configured to connect a first section of drill pipe to a second section of drill pipe in a serial fashion. Some system implementations can use a plurality of said addressable components. The one “male” and one “female” thread configuration can be a preferred implementation since drillpipe sections are configured similarly, i.e. one “male” and one “female” as fasten in a serial fashion when lowered into the wellbore via rig derrick.

In Wireline applications, multiple addressable components can mechanically fasten to multiple cabled sections. Without limitation, the mechanical fastener can also use similar forms of threaded “male/female” configurations. Thus, the Wireline system implementations can comprise of addressable components connected in a serial fashion with at least one cabling connection between two addressable components. Other implementations can comprise of multiple cabling and addressable components connected in a serial fashion with the addressable components communicating along the cabling components. In addition, each addressable component can implement, e.g., as software, firmware, hardware (or combinations of them), a data transmission protocol to receive and re-transmit the signals in either direction.

The wellbore telemetry system 112 is connected to a system 114 outside and at a terranean surface. In some implementations, the system 114 is a computer system, e.g., a desktop computer, a laptop computer, a server computer, a smartphone, a tablet computer, a personal digital assistant, or any other suitable computer. The system 114 includes a computer-readable medium 116 storing instructions executable by data processing apparatus 118 to perform signal transmission and reception operations with the logging instrument 108.

The wellbore telemetry system 112 can implement tethered communication devices, e.g., electrical cables, fiber optics, twisted pair, co-axial cables, or any other tethered communication device to transmit signals between the system 114 and the logging instrument 108. The system 114 can be a computer system that transmits command signals to the wellbore telemetry system 112, e.g., to each addressable component, the logging instrument 108, the tool 104, or combinations of them. The logging instrument 108 transmits collected data to the system 114 through the wellbore telemetry system 112. For example, the logging tool 108 transmits the collected data uphole to the addressable component that is nearest to the logging tool 108, e.g., addressable component 110 c. Addressable component 110 c receives the data and re-transmits the data uphole to the next serially connected addressable component, e.g., addressable component 110 b. In this manner, the addressable components serially receive and re-transmit the collected data from the logging instrument 108 to the system 114.

In some implementations, the system 114 includes an evaluation computer system to evaluate the multiple, serially connected addressable components in the wellbore telemetry system 112. The evaluation computer system can alternatively be implemented separately from the system 114 at the surface to transmit the multiple evaluation signals in a sequence downhole toward a device disposed downhole in the wellbore 102. The device can be, e.g., the logging instrument 108. In some implementations, the evaluation computer system can be implemented in any one of the addressable components in the wellbore telemetry system 112. By doing so, one addressable component can be implemented to evaluate itself and other addressable components in the wellbore telemetry system 112.

The evaluation computer system is configured to serially transmit multiple evaluation signals to the multiple serially connected addressable components. Each addressable component is addressable by a respective one of the multiple evaluation signals, described below with reference to FIG. 2, that the evaluation computer system transmits. In response to serially transmitting the multiple evaluation signals, the evaluation computer system is configured to evaluate the multiple communication links to the multiple addressable components based on multiple responses to the multiple evaluation signals. By doing so, the system 114 can identify impaired or faulty addressable components in the wellbore telemetry system 112. Alternatively, the evaluation computer system can be implemented downhole to transmit the multiple evaluation signals uphole from a device, e.g., the logging instrument 108, toward the system 114 at the surface of the wellbore 102. For example, the evaluation computer system can be connected to or be included in the logging instrument 108.

The addressable components operate collectively to transmit data collected by the logging instrument 108 in real time, i.e., without substantial delay after the logging instrument 108 obtains the data. An addressable component can be impaired or be faulty because of a faulty, e.g., broken, communication link that connects the addressable component to other addressable components or a faulty wire, cable or other communication device that connects the addressable component to the system 114 or to the logging instrument 108. The addressable component can be impaired, e.g., due to random noise at a depth in the wellbore 102 at which the addressable component is positioned or due to temperature variations at the addressable component's location (or combinations of them). Due to stochastic aspects experienced by each addressable component, there is a probability of error associated with each addressable component. An impaired or faulty addressable component can operate with the probability of error that is greater than an acceptable threshold probability caused by issues, e.g., battery loss, mechanical issues (e.g., wear, shock), environmental reasons, or any issue that affects data transmission in the uphole or downhole directions. The evaluation computer system can implement techniques to identify such an impaired or faulty addressable component as well as the addressable component's location in the wellbore 102.

FIG. 2 illustrates example communication signals exchanged by the system 114 that includes the evaluation computer system and the addressable components. At 202, the system 114 transmits a first evaluation signal, e.g., a synchronize (SYN) packet, to a first addressable component 110 a. At 204, the first addressable component 110 a receives the first evaluation signal, and, at 206, transmits a response, e.g., a synchronize-acknowledge (SYN-ACK) packet, to the first evaluation signal to the system 110 a. The first evaluation signal can uniquely address the first addressable component 110 a, and no other addressable components receiving the signal will respond. Similarly, a response from the first addressable component 110 a can enable the evaluation computer system to determine that the response is from the first addressable component 110 a.

Additional implementations of the evaluation signaling employed by the evaluation computer can comprise of transmitting a variety of packet sequences encoded and modulated in multiple encoded signaling formats varying in data rate and/or power. An addressable component can comprise of a receiver for at least one of the encoded signaling formats; a transmitter for sending a confirmation signal (e.g. ACK or acknowledge, a confirmation of various diagnostic and/or configuration information); and a processor enabled to conduct diagnostic calculations on said received signaling and encode a formatted response for signaling with said transmitter. In some implementations, the evaluation signaling can comprise of special commands within each encoded signaling format. These special commands can comprise instructions for conducting connection diagnostics for at least one data rate with at least one other addressable component deeper in the wellbore.

In some implementations, the confirmation signal can comprise of encoded diagnostic and/or configuration information (i.e. fastest received data rate, version number, received power level, etc.). The computer system can then wait a first specified duration threshold (i.e. a first time-out period) after sending the evaluation signal to a first addressable component before determining if the first addressable component is limited in configuration or in a fault state. In the absence of a received confirmation signal response from the first addressable component prior to an expiration of the first specified duration, the computer system can then determine/conclude the first addressable component is in a state of fault or the communications with the first addressable component is limited or impaired. On the other hand, the computer system can receive a confirmation signal from the first addressable component within the first specified duration threshold.

In some implementations, the computer system and/or addressable components can construct and transmit command instructions to then further command a second (or at least one other) addressable component to transmit a second evaluation signal to a second addressable components. Some addressable implementations can then transmit a second evaluation signal to a second addressable component and receive a second confirmation signal. For systems comprising of two or more addressable components, the computer system can then wait a second specified duration threshold before determining if a second addressable component is limited in configuration (or the effective channel between the computer system and the second addressable component restricts communications, or if the second addressable component is in a fault state, etc.).

Thus, there are many implementations of the disclosure. For example, the concepts described here can be extended to three or more addressable components as described with reference to FIG. 5, which illustrates another example communication exchange by an evaluation computer system and addressable components. At 502, the system 114 transmits an evaluation signal to a first component 110 a. At 504, the first component 110 a receives an evaluation signal from a component that is shallower in the wellbore than the first component 110 a. At 506, the first component 110 a transmits a confirmation signal to system 114, which the system 114 receives at 508. For example, the first component 110 a transmits the confirmation signal within a specified duration failing which the system 114 determines that the first component 110 a is faulty or impaired.

At 510, the first component 110 a transmits an evaluation signal to a component deeper in the wellbore (e.g., the second component 110 b). At 512, the second component 110 b receives the evaluation signal from the first component 110 a. At 514, the second component 110 b transmits a confirmation signal to the first component 110 a, which the first component 110 b receives at 516. At 518, the first component 110 b transmits a confirmation signal to the system 114 indicating the receipt of the confirmation signal from the second component 110 b. For example, the second component 110 b transmits the confirmation signal to the first component 110 a within the specified duration failing which the first component 110 b does not transmit the confirmation signal to the system 114. In response to not receiving the confirmation signal from the first component 110 a, the system 114 determines that the second component 110 b is faulty or impaired.

At 520, the second component 110 b transmits an evaluation signal to a component deeper in the wellbore (e.g., the third component 110 c), but receives no response to the evaluation signal. Because the second component 110 b does not receive a confirmation signal from the third component 110 c, the second component 110 b does not send a confirmation signal to the first component 110 a, which, in turn, does not send a confirmation signal to the system 114. After a specified duration expires (e.g., time out at 526), the system 114 determines a fault (or impairment) at the third component 110 c at 528.

FIG. 6 illustrates another example communication exchange by an evaluation computer system and addressable components. Similarly to FIG. 5, at 602, the system 114 transmits an evaluation signal to a first component 110 a. At 604, the first component 110 a receives an evaluation signal from a component that is shallower in the wellbore than the first component 110 a. At 606, the first component 110 a transmits a confirmation signal to system 114, which the system 114 receives at 607. For example, the first component 110 a transmits the confirmation signal within a specified duration failing which the system 114 determines that the first component 110 a is faulty or impaired.

At 608, the first component 110 a transmits an evaluation signal to a component deeper in the wellbore (e.g., the second component 110 b). At 610, the second component 110 b receives the evaluation signal from the first component 110 a. At 612, the second component 110 b transmits a confirmation signal to the first component 110 a, which the first component 110 b receives at 614. At 616, the first component 110 b transmits a confirmation signal to the system 114 indicating the receipt of the confirmation signal from the second component 110 b. For example, the second component 110 b transmits the confirmation signal to the first component 110 a within the specified duration failing which the first component 110 b does not transmit the confirmation signal to the system 114. In response to not receiving the confirmation signal from the first component 110 a, the system 114 determines that the second component 110 b is faulty or impaired.

At 618, the second component 110 b transmits an evaluation signal to a component deeper in the wellbore (e.g., the third component 110 c). At 620, the third component 110 c receives an evaluation signal from the component shallower in the wellbore, e.g., the second component 110 b. At 622, the third component 110 c transmits the confirmation signal to the second component 110 b, which the second component 110 b receives at 624. At 626, the second component 110 b transmits a confirmation signal to the first component 110 a indicating a receipt of the confirmation signal from the third component 110 c. At 628, the first component 110 a receives the evaluation signal from the second component 110 b. At 630, the first component 110 a transmits a confirmation signal to the system 114 indicating a receipt of the confirmation signal from the second component 110 b. In response to receiving the confirmation signal, the system 114 determines that the third component 110 c is functioning as intended. In some implementations, evaluation signals and confirmation signals can be exchanged directly between the first component 110 a and the second component 110 b, and between the second component 110 b and the third component 110 c. In some implementations, the evaluation signals and confirmation signals can be exchanged through intermediate addressable components between the first component 110 a and the second component 110 b, and between the second component 110 b and the third component 110 c.

Thus, a system can comprise of three or more addressable components, and the computer system can further wait for three or more additional specified duration thresholds (see FIG. 5) before determining a fault condition. These predetermine duration thresholds can be proportional to the time needed to handshake a round trip to each corresponding addressable component, respectively.

The system 114 evaluates the communication link to the first addressable component 110 a based on the response. In some implementations described below with reference to FIG. 3, the evaluation computer system can transmit the first evaluation signal multiple times to the first addressable component 110 a and evaluate the communication link based on a number of responses from the first addressable component 110 a. For example, the evaluation computer system can implement the process 300 to evaluate the first addressable component 110 a.

At 302, the evaluation computer system can transmit the first evaluation signal to the addressable component 110 a, and, at 304, check for a response. At 306, the evaluation computer system can perform a check to determine if the first evaluation signal has been transmitted to the first addressable component 110 a a threshold number of times (e.g., 10 times). If the first evaluation signal has not been transmitted a threshold number of times (decision branch “NO” in FIG. 3), then the evaluation computer system can continue to transmit the first evaluation signal to the first addressable component 110 a and check for a response. In this manner, the evaluation computer system can transmit the first evaluation signal multiple times to the first addressable component 110 a.

If the first addressable component 110 a is operating without any fault, then the first addressable component 110 a would have responded to each instance of receiving a first evaluation signal from the evaluation computer system. At 308, the evaluation computer system can determine a number of responses (e.g., 3 or 5 or 7) to transmitting the first evaluation signal to the first addressable component 110 a multiple times (e.g., 10 times). At 310, the evaluation computer system can determine a ratio of a number of responses (e.g., 3 or 5 or 7) to a number of transmissions (e.g., 10). A response from the first addressable component 110 a can be merely an acknowledgement of receipt of the first evaluation signal. Alternatively or in addition, the response can include data describing a status of the first addressable component 110 a.

At 312, the evaluation computer system can perform a check to determine if the determined ratio (e.g., 0.3 or 0.5 or 0.7) satisfies a threshold ratio (e.g., 0.6). If the threshold ratio is satisfied (decision branch “YES”), then the evaluation computer system can determine that the first addressable component 110 a is functioning properly (i.e., is not impaired and is without fault) at 314. If the threshold ratio is not satisfied (decision branch “NO”), then the evaluation computer system can determine that the first addressable component 110 a is impaired or is faulty (or both) at 316. In some implementations, the evaluation computer system may not determine a ratio described above. Instead, the evaluation computer system can determine if a number of responses satisfied a threshold number of responses. In this manner, the evaluation computer system can determine if a communication link to the first addressable component 110 is performing optimally or has failed based on a number of responses to multiple transmissions of the first evaluation signal to the first addressable component 110 a.

Returning to FIG. 2, after receiving the response from the first addressable component 110 a, at 210, the computer system 114 transmits a second evaluation signal to the second addressable component 110 b. The second addressable component 110 b is the next, successive addressable component in the series of addressable components included in the wellbore telemetry system 112. The evaluation computer system can evaluate the first addressable component 110 a (or any addressable component or addressable components ahead of the second addressable component 110 b) while transmitting the second evaluation signal to the second addressable component 110 b. In other words, the transmission of multiple evaluation signals to multiple addressable components occurs in series, i.e., one addressable component at a time. In addition, after an evaluation signal is received from an addressable component, a next evaluation signal is transmitted to a successive addressable component. However, evaluation of the addressable components based on responses received from the addressable components can occur in parallel with the transmission of the evaluation signals. For example, after the evaluation computer system receives a response (or responses) from the first addressable component 110 a, the evaluation computer system can evaluate the first addressable component 110 a and transmit a second evaluation signal to the second addressable component 110 b in parallel.

The second addressable component 110 b receives the second evaluation signal at 212. At 214, the second addressable component 110 b transmits a response to the second evaluation signal to the system 114. Similarly to the first evaluation signal, the second evaluation signal can uniquely address the second addressable component 110 b. Also, a response from the second addressable component 110 b can enable the evaluation computer system to determine that the response is from the second addressable component 110 b.

The system 114 evaluates the communication link to the second addressable component 110 b based on the response. In some implementations described below with reference to FIG. 4, the evaluation computer system can transmit the second evaluation signal at a particular data rate to the second addressable component 110 b and evaluate the communication link based on responses from the second addressable component 110 b. For example, the evaluation computer system can implement the process 400 to evaluate the second addressable component 110 b.

At 402, the evaluation computer system can transmit the second evaluation signal to the second addressable component 110 b at a data rate. At 404, the evaluation computer system can perform a check for a response. If the evaluation computer system does not receive a response to the second evaluation signal at the data rate, then the evaluation computer system can determine that the second addressable component 110 b is impaired or is faulty. The evaluation computer system can expect a specific response to a specific message included in the second evaluation signal. Not receiving a response can include failure to receive the specific response. In other words, even if the second addressable component 110 b provided a response to the second evaluation signal, the evaluation computer system can nevertheless determine that the second addressable component 110 b is impaired or is faulty if the response is not one that the evaluation computer system expected.

In response to determining that the second addressable component 110 b is impaired or is faulty, at 406, the evaluation computer system can decrease a data rate of the second evaluation signal, e.g., from a first data rate to a second data rate that is less than the first data rate. The evaluation computer system can transmit the second evaluation signal at the decreased data rate to the second addressable component 110 b and check for a response. The evaluation computer system can continuously decrease the data rate of the second evaluation signal until the second addressable component 110 b responds, e.g., a threshold number of times.

If the evaluation computer system receives a response, then the evaluation computer system can conclude that the second addressable component 110 b is operating without fault at a data rate at which the second addressable component 110 b responded to the second evaluation signal. In some implementations, the evaluation computer system can transmit the second evaluation signal at the data rate multiple times to the second addressable component 110 b. By implementing techniques similar to those described above with reference to FIG. 3, the evaluation computer system can determine that a number of responses from the second addressable component 110 b satisfies a threshold number of responses, and, accordingly, determine that the second addressable component 110 b is operating optimally.

Returning to FIG. 2, after receiving the response from the second addressable component 110 b, at 218, the computer system 114 transmits a third evaluation signal to the third addressable component 110 c. The third addressable component 110 c is the next, successive addressable component in the series of addressable components included in the wellbore telemetry system 112. As described above, the evaluation computer system can evaluate the first addressable component 110 a or the second addressable component 110 b (or any addressable component ahead of the third addressable component 110 c) in parallel with transmitting the third evaluation signal to the third addressable component 110 c. In some implementations, to evaluate a communication link to the third addressable component 110 c, the evaluation communication system can detect an absence of a response to the third evaluation signal transmitted to the third addressable component 110 c, and, accordingly, at 220, determine that the third addressable component 110 c is faulty. In some implementations similar to those described above, the evaluation computer system can transmit the third evaluation signal multiple times to the third addressable component 110 c, and determine that the third addressable component 110 c is faulty upon detecting an absence of at least a threshold number of responses.

The evaluation computer system can be configured to implement the example evaluation techniques described above with reference to one addressable component to evaluate any of the other addressable components. For example, the evaluation computer system can evaluate the first addressable component 110 a by transmitting evaluation signals at different data rates, determine the second addressable component 110 b is faulty based on an absence of a response to the second evaluation signal, and evaluate the third addressable component 110 a based on a number of responses to transmitting the third evaluation signal multiple times. Also, as described above, the transmission of evaluation signals to the multiple addressable components occurs serially, i.e., one addressable component at a time. But, the evaluation of the addressable components can occur in parallel with each other and with the transmission of the evaluation signals.

In some implementations, the evaluation computer system can serially transmit the multiple evaluation signals to the multiple addressable components. For each addressable component, the evaluation computer system can continuously decrease a data rate of an evaluation signal, as described above, to identify a respective data rate at which each addressable component operates optimally. From the multiple data rates identified for the serially connected multiple addressable components in the wellbore telemetry system 112, the evaluation computer system can determine the smallest data rate. The smallest data rate represents the data rate at which all addressable components in the wellbore telemetry system 112 operate without fault. The system 114 can transmit through the multiple addressable components at the smallest data rate, thereby causing all addressable components to operate without bottlenecks.

As described above, an addressable component can include a battery to receive and re-transmit signals. An addressable component's battery can consume a certain power to operate the addressable component at a particular data rate. If the addressable component is configured to operate at a data rate that is greater than the smallest data rate, then the addressable component's battery may be operable at a power that is lower than the certain power. The evaluation computer system can determine that an addressable component, e.g., the addressable component repeater 110 b, is adapted to transmit data at a data rate that is greater than the smallest data rate at a first power. The system 114 can operate the second addressable component 110 b at a second power that is less than the first power, the second power sufficient to transmit data at the smallest data rate.

Implementations of the subject matter and the operations described in this disclosure, e.g., the evaluation computer system, the system 114, an addressable component, (or combinations of them) can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this disclosure and their structural equivalents, or in combinations of one or more of them. Implementations of the subject matter described in this disclosure can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on computer storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively or in addition, the program instructions can be encoded on an artificially-generated propagated signal, for example, a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus.

A computer storage medium, for example, the computer-readable medium, can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially-generated propagated signal. The computer storage medium can also be, or be included in, one or more separate physical and/or non-transitory components or media (for example, multiple CDs, disks, or other storage devices).

The operations described in this disclosure can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources. The term “data processing apparatus” encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations, of the foregoing. The apparatus can include special purpose logic circuitry, for example, an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). The apparatus can also include, in addition to hardware, code that creates an execution environment for the computer program in question, for example, code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them. The apparatus and execution environment can realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures.

A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Various implementation implementations can comprise of addressable components from any single or combination of the following (but not limited to) wellbore communication systems: mud pulse telemetry, electromagnetic telemetry, acoustic telemetry, twisted pair and/or coaxial cables, wired pipe, and/or fiber optic. Additionally, any pair of addressable components can utilize multiple physical channel medias and/or comprise of multiple receivers and multiple transmitters. These multiple-input and multiple-output communication implementation implementations can further comprise of a multitude of communication receivers and transmitters. 

1. A computer-implemented method to evaluate a wellbore telemetry system, the method comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a threshold number of times; determining a number of responses to transmitting the evaluation signal to the component the threshold number of times; and determining a ratio of the number of responses to the threshold number of times the evaluation signal is transmitted to the component.
 2. (canceled)
 3. The method of claim 1, further comprising determining that the communication link to the component has failed if the ratio is less than a threshold ratio.
 4. A computer-implemented method to evaluate a wellbore telemetry system, the method comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a number of times at a first data rate; determining that a number of responses to transmitting the evaluation signal to the component the number of times at the first data rate does not satisfy a threshold number; and in response to determining that the number of responses does not satisfy the threshold number, transmitting the evaluation signal to the component at a second data rate that is less than the first data rate.
 5. The method of claim 4, further comprising continuously decreasing a data rate at which the evaluation signal is transmitted to the component until the number of responses to transmitting the evaluation signal to the component satisfies the threshold number.
 6. The method of claim 5, further comprising: for each communication link of the plurality of communication links, identifying a respective data rate at which a number of responses to transmitting a respective one of the plurality of evaluation signals to a respective component satisfies a respective threshold number; from among a plurality of data rates identified for the plurality of communication links, identifying a smallest data rate; and transmitting data to the plurality of components at the smallest data rate.
 7. The method of claim 6, further comprising: determining that a component is adapted to transmit data at a data rate that is greater than the smallest data rate at a first power; and operating the component at a second power that is less than the first power, the second power sufficient to transmit data at the smallest data rate.
 8. The method of claim 1, wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: detecting an absence of the response to an evaluation signal transmitted to the component; and identifying the component as a faulty component.
 9. The method of claim 1, wherein the plurality of evaluation signals are transmitted in a sequence downhole from a computer system disposed at a surface of the wellbore toward a sensor disposed downhole in the wellbore.
 10. The method of claim 1, wherein the plurality of evaluation signals are transmitted in a sequence uphole from a sensor disposed downhole in the wellbore toward a computer system disposed at a surface of the wellbore.
 11. A wellbore telemetry system comprising: a plurality of serially connected components disposed in a wellbore, each component addressable by data signals; and a computer system comprising: data processing apparatus, and a computer-readable medium storing instructions executable by data processing apparatus to perform operations comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a threshold number of times; determining a number of responses to transmitting the evaluation signal to the component the threshold number of times; determining a ratio of the number of responses to the threshold number of times the evaluation signal is transmitted to the component; and determining that the communication link to the component has failed if the ratio is less than a threshold ratio.
 12. (canceled)
 13. A wellbore telemetry system comprising: a plurality of serially connected components disposed in a wellbore, each component addressable by data signals; and a computer system comprising: data processing apparatus, and a computer-readable medium storing instructions executable by data processing apparatus to perform operations comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a number of times at a first data rate; determining that a number of responses to transmitting the evaluation signal to the component the number of times at the first data rate does not satisfy a threshold number; and in response to determining that the number of responses does not satisfy the threshold number, continuously decreasing, relative to the first data rate, a data rate at which the evaluation signal is transmitted to the component until the number of responses to transmitting the evaluation signal to the component satisfies the threshold number.
 14. The system of claim 13, wherein the operations further comprise: for each communication link of the plurality of communication links, identifying a respective data rate at which a number of responses to transmitting a respective one of the plurality of evaluation signals to a respective component satisfies a respective threshold number; from among a plurality of data rates identified for the plurality of communication links, identifying a smallest data rate; transmitting data to the plurality of components at the smallest data rate; determining that a component is adapted to transmit data at a data rate that is greater than the smallest data rate at a first power; and operating the component at a second power that is less than the first power, the second power sufficient to transmit data at the smallest data rate.
 15. The system of claim 11, wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: detecting an absence of the response to an evaluation signal transmitted to the component; and identifying the component as a faulty component.
 16. The system of claim 11, wherein the computer system is disposed at a surface of the wellbore and transmits the plurality of evaluation signals downhole.
 17. The system of claim 11, wherein the computer system is disposed downhole in the wellbore and transmits the plurality of evaluation signals uphole.
 18. A non-transitory computer-readable medium storing instructions executable by data processing apparatus to perform operations comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a threshold number of times; determining a number of responses to transmitting the evaluation signal to the component the threshold number of times; determining a ratio of the number of responses to the threshold number of times the evaluation signal is transmitted to the component; and determining that the communication link to the component has failed if the ratio is less than a threshold ratio.
 19. (canceled)
 20. A non-transitory computer-readable medium storing instructions executable by data processing apparatus to perform operations comprising: serially transmitting a plurality of evaluation signals to a plurality of serially connected components of a wellbore telemetry system disposed in a wellbore, each component addressable by a respective one of the plurality of evaluation signals; and in response to serially transmitting the plurality of evaluation signals, evaluating a plurality of communication links to the plurality of components based on a respective plurality of responses to the plurality of evaluation signals; and wherein evaluating a communication link to a component based on a response to a respective one of the plurality of evaluation signals transmitted to the component comprises: transmitting an evaluation signal to the component a number of times at a first data rate; determining that a number of responses to transmitting the evaluation signal to the component the number of times at the first data rate does not satisfy a threshold number; and in response to determining that the number of responses does not satisfy the threshold number, continuously decreasing, relative to the first data rate, a data rate at which the evaluation signal is transmitted to the component until the number of responses to transmitting the evaluation signal to the component satisfies the threshold number.
 21. The method of claim 1, wherein a response to transmitting the evaluation signal to the component includes an acknowledgement of receipt of the evaluation signal.
 22. The method of claim 1, wherein a response to transmitting the evaluation signal to the component includes data describing a status of the component.
 23. The method of claim 1, further comprising determining that the communication link has failed in response to determining that the number of responses to transmitting the evaluation signal to the component is less than the threshold number of times.
 24. The method of claim 4, further comprising: transmitting the evaluation signal at the second data rate to the component a threshold number of times; determining a number of responses to transmitting the evaluation signal at the second data rate to the component the threshold number of times; and determining a ratio of the number of responses to the threshold number of times the evaluation signal is transmitted at the second data rate to the component. 